In community-acquired pneumonia, identification of the etiologic agent has theoretically important advantages. For individual patients, it facilitates the administration of a targeted, narrow-spectrum antibiotic therapy that may improve the efficacy of treatment, and reduces risks of antibiotic-related toxicity. For the community, microbiologic results contribute to understanding the local microbial epidemiology of community-acquired pneumonia and the antimicrobial resistance patterns of pathogens, information that is essential in the instauration or modification of empiric treatment regimens.